BIS 1B - Bis 1b Phylogeny Phylum Porifera: Sponges Body w/...

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Bis 1b Phylogeny Phylum Porifera: Sponges Body w/ pores, canals and chambers that allow for passage of water. o Choanocytes- flagellate collar cells that create water currents through the pores, canals, and chambers of the sponge. Radial Symmetry All adults remain sessile and attached to substratum. 3 Body Types (Varying Canal Systems): o Ascanoid Choanocytes line the spongocoel, the inner cavity. Small and Tube Shaped o Syconoid Choanocytes lie in the canals made by folding the body outwar o Leuconoids Body Form contains many small choanocyte line chambers Phylum Cnidaria Cnidocytes: stinging cells found throughout the phylum Class Hydrozoa “Hydra”- water serpent o Solitary or Colonial o Asexual Polyps and Sexual Medusae o Medusae w/ Velum o Ex: Man o’ War, hydra, hydroids Class Scyphozoa o Solitary o Polyp stage reduced or absent o Bellshaped medusae without velum o Ex: Large Jellyfish Class Cubozoa o Polyp stage reduced o Cuboidal Medusae o Class Anthozoa o Polyps Only Can be large o Solitary or Colonial o Phylum Platyhelminthes (Flatworms) Basic Body Plan: o Bilateral Symmetry, w/ distinct anterior and posterior o Three Primary Germ Layer: Ectoderm, Mesoderm and Endoderm
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o Body dorso-ventrally flattened. Oral and genital opening on ventral surface. Class Turbellaria o Paraphyletic o Ex: Sea Worms Class Trematoda o Flukes Liver Fluke Class Monogenea o Ectoparasite Class Cestoda o Tapeworms o Scolices Suckers Phylum Annelida Basic Features: o Segmented (also called metameric) Each segment separated by a septa o Hydostatic Skeleton o True Coelom o Close Circulatory system o Complete Gut o Longitudiunal and circular muscles o Setae (bristles) used as anchors or for swimming o Trochophore Larva Class Polychaeta (Marine Worms) o Some are active predators w/ strong jaws and venomous bites o Some are filter feeder that live in tubes and filter particles out of the water o Som like the parchment worm pump water into its tube and filter particles in secreted mucous Class Oligochaeta (Earth Worms) o Use setae to aid in burrowing o Can be very big--up to several meters long o Critical part of the Soil biota Class Hirudinea (Leeches) o ½ are predaceous/scavengers and ½ are parasitic o
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This note was uploaded on 04/15/2008 for the course BIS B taught by Professor Renee during the Fall '06 term at UC Davis.

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BIS 1B - Bis 1b Phylogeny Phylum Porifera: Sponges Body w/...

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